The Pittsburgh-Allegheny County Sports & Exhibition Authority says it is under no obligation to pay for two-thirds of the cost of a proposed 3,000-seat expansion at Heinz Field.

In a formal response to a lawsuit filed in December by the Steelers, the SEA contends that the proposed expansion does not meet the definition of a capital improvement in the team's stadium lease.

While the Steelers maintain that Heinz Field ranks 25th out of 31 NFL stadiums in terms of seating capacity, the SEA, in its response, argued that the proposed expansion does not meet the definition of a capital improvement because the addition or modification has not been installed in at least half of all league facilities, with at least 25 percent of the cost being paid for by federal, state or local governments.

In fact, the SEA contended that far less than half of all stadiums in the NFL have had such modifications of additions where no less than 25 percent of the cost was funded by the various levels of government.

The team, the response stated, apparently interprets the relevant lease clause "as giving it the right to obtain a seat expansion of up to 10,000 additional seats . . . just by demanding such without meeting the capital improvement criteria."

In its lawsuit, the team argued that a clause in the lease requires the SEA to pay two-thirds of the cost of a "designated expansion" of no more than 10,000 seats in the south end zone. It maintained that the proposed expansion, which would cost $40 million, qualifies as a designated expansion that is automatically deemed to be a capital improvement. The SEA denied that.