HOUSTON, July 27 (Reuters) - U.S. shale producers have started to trim their 2017 capital spending budgets, a tacit acknowledgement that such plans were too aggressive when crafted months ago before commodity prices weakened.

This week alone, Anadarko Petroleum Corp, ConocoPhillips, Whiting Petroleum Corp and Hess Corp cut a combined $750 million from their capex plans, each citing weaker-than-expected oil prices.

The quartet are just the first in a wave of oil industry earnings results expected over the next two weeks, with many analyst expecting peers including Noble Energy Inc and Marathon Oil Corp to cut their own spending in order to appease Wall Street’s demands for fiscal restraint.

“We sincerely believe the volatility of the current operating environment requires financial discipline,” Anadarko Chief Executive Al Walker told investors on Tuesday.

“Pursuing growth without adequate returns is something we will avoid.”

The cuts partly seem designed to appease Wall Street’s fixation on cash flow, even though some companies have strong balance sheets. Shares of Conoco rose 1.6 percent on Thursday, with shares of Anadarko up 1.5 percent.

Hess, for instance, cut $100 million from its 2017 spending plans despite having $2.5 billion in cash stored away. Anadarko cut $300 million, but has more than $6 billion in the bank.

“In the current low price environment, we continue our efforts to reduce both capital and operating costs,” Hess Chief Executive John Hess told investors on Wednesday.

The cuts also came without plans to cut back on the number of rigs drilling into U.S. shale formations.

Increasing rig efficiency has meant U.S. shale producers can do more while spending less. In North Dakota, the No. 2 U.S. oil-producing state, Hess said it can now drill with four rigs the same number of wells that last year took six.

That improvement likely will continue to roil the Organization of the Petroleum Exporting Countries, who have tried to offset rising U.S. shale oil production with cuts of their own.

Shares of some oilfield service providers, which drill and frack wells for producers, have slipped as the capex decisions have been announced, with shares of Halliburton Co down more than 5.0 percent in the past week. (Ernest Scheyder)