(Reuters) - Intel Corp (INTC.O) is in talks to buy fellow chipmaker Altera Corp (ALTR.O) in a deal that would likely top $10 billion, marking the latest merger in the semiconductor business, the Wall Street Journal reported on Friday.

An acquisition of Altera, which makes programmable chips widely used in cellphone towers, the military and other industrial applications, underscores Intel Chief Executive Officer Brian Krzanich's determination to expand into new markets as the personal computer industry looses steam.

Terms of the potential deal and its timing were not known, the Journal said.

Intel declined comment on what would be its largest takeover ever if a deal were to be reached. Altera did not immediately respond to a request for comment.

Intel, the world's largest chipmaker, and Altera have already been forming a close relationship.

In 2013, Intel agreed to manufacture chips on behalf of Altera, a major change for the world's top chipmaker, which traditionally has been unwilling to share its cutting-edge technology. Since then the two companies have also expanded their cooperation to include other kinds of chip development.

Shares of Altera, valued at $10.4 billion at Thursday's close, were up 24.5 percent at $43.16 per share on the Nasdaq on Friday. Intel shares were up 6.4 percent to $32 onNasdaq.