* Request for proposals expected in weeks

* Number of shipyards could compete later (Adds details, quotes)

MOBILE, Ala., Jan 4 - The U.S. Navy expects to issue a request for proposals for 10 new shallow-water warships within weeks, a top Navy official said on Monday.

Rear Admiral Jim Murdoch, program manager for the Navy's new Littoral Combat Ship, acknowledged the Navy was running about a month late with its revised acquisition procedure, but said: It'll be out soon. We are resolving a number of industry questions. He said the new terms for the competition to build more LCS ships should be out within weeks, not months.

Murdoch spoke during a tour of the USS Independence, the first LCS ship completed by General Dynamics Corp (GD.N), which is due to be commissioned on Jan. 16.

Lockheed Martin Corp (LMT.N) has built a different design of LCS ship for the Navy. It went into service in late 2008.

Each of the two companies has begun work on a second ship.

The Navy initially intended to proceed with both designs, but decided last September to save money by picking a single design in 2010 and then allowing other shipyards to compete later to build that same design.

Industry executives are concerned that whichever company loses the initial competition could be locked out of the second source competition later on.

Murdoch said each case is different, but he was confident that a number of U.S. shipyards would be able to compete for those second source contracts, regardless of which ship design was chosen. He did not give details on the shipyards.

Murdoch also reiterated the Navy's intention to buy a total of 55 of the new shore-hugging, more agile warships, saying that goal had not wavered during the recent budget negotiations despite the rise in the price tag of the new ships.

The ships were initially slated to cost no more than $220 million, but the Navy later asked Congress to raise the cost cap to $460 million. The cost cap takes effect from fiscal 2010.

The Navy last month said Lockheed's second ship would cost $471 million, plus $78 million in material already purchased earlier, putting the total cost of the ship at around $549 million. That is far below the $637 price tag for its first LCS ship, but still above the cost cap.

The second General Dynamics ship is slated to cost $434 million, plus $114 million in materials already purchased, for a total cost of $548 million. That compares to a total price of $704 million for its first ship.

Improved manufacturing techniques and lessons learned from work on both first ships will help the companies and the Navy keep costs down on the second ships, Navy officials and industry executives say.

They note that the second ships are also being built under a fixed-price contract, which makes it harder for the government to make expensive changes, and forces industry to keep a lid on cost growth. (Reporting by Andrea Shalal-Esa; Editing Bernard Orr, Gary Hill)