In the latest salvo in their protracted takeover battle, Men's Wearhouse said it might be willing to sweeten its bid for rival Jos. A. Bank Clothiers in a letter sent Thursday to Bank's independent directors.

Men's Wearhouse urged the directors to form a special committee to reconsider its offer to buy Bank for $1.6 billion cash and begin negotiations. It said it might increase its $57.50-a-share offer for the Hampstead-based men's retailer if it found additional value during negotiations or due diligence.

Bank declined to comment Thursday on the latest overture from Men's Wearhouse.

Bank started the takeover battle last fall when it offered to buy Houston-based Men's Wearhouse for $2.3 billion to create a men's apparel behemoth with 1,700 stores. Men's Wearhouse spurned that bid, but countered with an offer to buy Bank in November that it too rejected.

Many analysts believe a combination of the retailers makes sense and all that remains to be determined is which company is in control. At least one large stockholder — the New York hedge fund Eminence Capital — is pressuring Bank to accept the offer.

Meanwhile, BlackRock, a large New York-based investment manager, increased its stakes in both Men's Wearhouse and Bank late last year. As of Dec. 31, it owned 8.7 percent of Men's Wearhouse and 9.4 percent of Bank.

Bank shares rose 85 cents to $55.81 each Thursday, while Men's Wearhouse stock went up 90 cents to $47 a share.