With congressional leaders still scrambling to reach an agreement to raise the federal borrowing limit, some U.S. companies are beginning to prepare for the uncertainty that would follow a government default or a potential downgrade of the country’s credit rating.

Some companies are increasing their cash reserves, though industry groups and analysts say business leaders remain confident that Congress can reach an agreement to raise the debt ceiling before a key Aug. 2 deadline.

“We always engage in contingency planning, but we believe that Congress will address the debt ceiling and deficit issues,” said Scott Talbott, senior vice president of government affairs for the Financial Services Roundtable. The industry group is holding conference calls with its members twice a day, and it sent a letter to House members Thursday urging support for legislation sponsored by Speaker John A. Boehner (R-Ohio) to raise the debt ceiling.

In the meantime, chemical company FMC, which gets about two-thirds of its sales overseas, is hedging against a potential decline in the value of the dollar after a default or downgrade. “We’re working to make sure we have more than enough foreign exchange lines,” said Thomas C. Deas, FMC’s vice president and treasurer.

Inspiring some of the contingency planning are memories of the 2008 financial crisis, when many companies faced a credit crunch. “What we learned in 2008 is that liquidity is everything, and we’re applying those lessons here to make sure we have more than enough funds to operate our business,” Deas said.

About half of the 302 companies recently surveyed by the Association for Financial Professionals said they were likely to take no action if there is a federal default or downgrade. But that appears to be changing, said Tom Hunt, the association’s director of treasury services. During an online meeting with some members Thursday, about 60 percent said they were holding more cash to hedge against a potential government default, he said.

“There is more urgency to hold more liquidity than there was an even a week ago,” Hunt said.

Some companies also plan to avoid the capital markets — issuing debt or trying to raise money — in the days surrounding the deadline, he said.

Fifth Third Asset Management, which manages about $17 billion in assets, began preparing for a potential debt-ceiling showdown last spring after Congress’s wrangling over the last budget. “Congress was having an ugly debate back then, and the numbers were so inconsequential,” said Keith Wirtz, the firm’s chief investment officer. “That gave us a sense that it was time to start to dial back.”

The firm began increasing its portfolios’ cash positions from 2 percent to about 10 percent, Wirtz said. He said that the possibility of a government default remains remote but that there is more concern about a credit-rating downgrade.