While using polite language in a short, precise letter, IBM has basically told two U.S. Senators to mind their own business.

Responding to criticism from Vermont U.S. Senators Patrick Leahy and Bernie Sanders about changes in Big Blue’s 401(k) plan that has upset many IBM employees, the company’s top human resources executive has basically told them to mind their own businesses.

No restoration of previous practices will be made in the interest of competitiveness, IBM (NYSE: IBM) says.

A copy of a letter IBM Senior Vice President for Human Resources Randy MacDonald sent to the senators was obtained by Alliance at IBM, the union seeking to represent IBM workers, and published on its website the same day.

“With reference to the issue you wrote about, we observed that other companies have already moved away from biweekly contributions,” MacDonald wrote.

“We designed our plan to remain competitive while maintaining our industry leading company match and automatic contribution that our employees appreciate.

“This change helps us maintain business competitiveness in an uncertain economic environment, while allowing us to invest billions of dollars in employee compensation and benefits programs each year.

“A more competitive IBM is in the interests of all our constituents – employees, clients and shareholders.”

MacDonald didn’t address other concerns raised by the senators.

They noted that IBM has cut its U.S. work force “by nearly half” over the last decade and pointed out that the change in the 401(K) plans means employees not only aren’t receiving matching funds biweekly but only annually – and only if they are on the payroll as of Dec. 15 each year.

Numerous IBMers have expressed fears that they will be laid off as part of a “resource action” or lose their jobs in other ways before Dec. 15, thus being denied 401(k) matches.

Rather, MacDonald chose to defend IBM’s 401(k) plan.

It is “among the best plans” in the U.S. with “one of the highest company contributions in the country” while leading “the industry with low fees.” Further, IBM offers workers “personal financial planning” services “at no cost.”

“You would be hard pressed to find many other companies that offer such an attractive plan to its employees in Vermont, or any state,” MacDonald said.

Meanwhile, IBM, which employs an estimated 10,000 people across North Carolina, has decided to move an undisclosed number of manufacturing jobs out of Minnesota to Mexico, its shares reached an all-time high earlier this week and Big Blue disclosed that its top two executives in 2012 earned more than $38 million in salary, benefits and stock.

[IBM ARCHIVE: Check out more than a decade of IBM stories as reported in WRAL Tech Wire.]