Steven Barg, UBS's head of global capital markets for Asia, has resigned from his post, a source with direct knowledge of the matter said, marking a blow to the bank's regional ECM franchise.

The source said Barg is expected to move to Goldman Sachs . UBS and Goldman declined comment.

Barg, an American and a graduate of Wesleyan University in Connecticut, could not immediately be reached for comment.

IFR was first to report Barg's resignation.

For years, UBS has led the equity capital markets (ECM) league tables in Asia, a business built up by the former regional head of the investment bank, Robert Rankin, who left for Deutsche Bank last year.

UBS was the top underwriter during last year's IPO boom in Hong Kong, where the city saw more listings than any other in the world, according to Thomson Reuters data.

The bank was involved with $4.3 billion worth of Hong Kong IPOs from January 1 until mid-December, ahead of Morgan Stanley with $3.9 billion.

A Thomson Reuters fee analysis showed UBS pulled in $93.3 million in estimated fees from 11 IPOs completed in the same period and also topped Morgan Stanley for the No. 1 fee slot.

Goldman Sachs ranked No. 7 in the same rankings of Hong Kong IPO proceeds.

Cracks in UBS's ECM structure appeared earlier this month. Reuters reported on May 6 that Mark Williams, head of UBS Asia equity capital markets, resigned to join Japanese brokerage Nomura Holdings <8604.T>.

UBS filled that role with two senior appointments, including Williams' friend and former Hong Kong colleague, Sam Kendall.

One black spot recently left on UBS's ECM reputation was its failure to make the underwriting team for the $30 billion Agricultura Bank of China IPO. While UBS was chosen a financial adviser on the deal, it was left out of the lucrative chance of syndicating the offering.

UBS also did not make the cut for the fund raising by Bank of China.

(Editing by Jacqueline Wong and Anshuman Daga)